JPS5815791B2 - Denshi Fukushi Yakinio Kergen Zosouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device for an electronic copying machine, and more particularly to a sleeve rotating magnetic roller developing device.

In the field of electrophotography, a variety of developing methods have been proposed for converting the electrostatic latent image formed on the photoreceptor into a visible image, but the magnetic roller developing method is more effective than other methods. It is possible to obtain reproduced images with excellent continuous tone reproducibility and fidelity, and for this reason it has been adopted in some commercially available electronic copying machines.

The developing device used in the above method is composed of a hollow cylindrical sleeve and a magnet placed therein. Either the sleeve or the magnet is rotated to transfer the developing material from a predetermined position to the surface of the photoreceptor. Develops an electrostatic latent image on the body surface.

Sleeve-rotating sugenet roller developers are better suited for transporting large amounts of developer material at one time than magnet-rotating magnet roller developers, but they do not transfer developer material from the developer to other parts of the copier. It is difficult to prevent the scattering of the developer, resulting in drawbacks such as an increase in developer consumption and contamination of the copying machine due to the developer scattering.

Conventional magnetic roller developing devices prevent developer material from scattering by interposing an elastic body such as sponge, gauze, or felt between the framework of the developing device and the rotating sleeve. If a rotating member and a fixed member are always kept in contact with each other, the contact surface will generate heat, which will have an adverse effect on the device.Also, even if a porous elastic body such as a sponge is used, the material will naturally deteriorate. The ability to prevent scattering of developer material was limited, and satisfactory results could not be obtained.

The present invention has been made in view of the above drawbacks.

In the developing device of the present invention, regions are provided at both ends of the rotating sleeve that do not face the magnets fixed inside, and a developer adsorption member is provided close to the regions and along a part of the circumferential surface of the rotating sleeve. By attaching the developer material, the developer material scattered as the sleeve rotates is attracted to the developer material adsorption member, thereby preventing the developer material from escaping from the developing device.

More preferably, a spiral groove is provided in the area, and the groove is formed to be inclined in a direction that moves the developer material on the area inward when viewed from the axial direction when the sleeve rotates;
Therefore, while the sleeve is rotating, there is always a force acting on the developer material to move it inside the sleeve, so if the groove is provided in the rotating sleeve in combination with the developer adsorption member described above, scattering of the developer material can be more effectively prevented. It can be prevented.

Therefore, the first object of the present invention is to provide a rotating sleeve magnet having a mechanism for preventing developer material from scattering from a developing device.
An object of the present invention is to provide a roller developing device.

Another object of the present invention is to provide a sleeve-rotating magnetic roller developing device having a simple structure and an inexpensive developer material scattering prevention mechanism.

Another object of the present invention is to provide a sleeve rotation type magnetic roller developing device equipped with a developer collection mechanism.

Next, a preferred embodiment of the present invention illustrated in the drawings will be explained.

FIG. 1 is a schematic cross-sectional view of a sleeve-rotating magnetic roller developing device according to the present invention, and FIG. 2 is a cut-away pressure surface view of the device shown in FIG.

Numeral 1 indicates a drum-type photoreceptor having an electrostatic latent image on its surface, and the photoreceptor is rotated in the direction of arrow A by a drive device (not shown).

The electrostatic latent image on the photoreceptor 1 is formed by appropriate means.

The developing device according to the present invention, generally indicated by the numeral 2, has a predetermined amount of developer material 4 stored in a developer container 3 .

A fixed shaft 5 is installed in the developing device 2 so as to be parallel to the axis of the photoreceptor 1, and the fixed shaft 5 is made of, for example, iron, brass, or the like.
It can be made of either a magnetic material such as aluminum or a non-magnetic material, and a fan-shaped bar-shaped cross-sectional magnet assembly 6 is arranged on the fixed shaft 5 in a non-rotatable manner.

In the illustrated example, the magnet assembly 6 includes ten bar-shaped magnet pieces 7 in a fan-shaped cross section that are fixed to the fixed shaft 5 adjacent to each other, and each magnet piece 7 has a circumferential portion opposite to that of the adjacent magnet piece. It has a polarity of .

The magnet assembly 6 is formed not only by combining magnetized small pieces, but also by arranging a cylindrical or semi-cylindrical magnetizable material on the circumferential surface of the fixed shaft 50 and using an appropriate magnetization means to form the magnet assembly shown in FIG. 1, for example. They may also be formed by magnetizing them in an array such as the body 6.

The sleeve 8 can be made of a non-magnetic material such as aluminum, brass, or certain stainless steel, and is attached to the fixed shaft 5.
and is rotatably disposed concentrically and rotatably with the developing device, and is rotated in the direction of arrow B by a suitable drive device (not shown), such as an electric motor, when the developing device is in use.

A portion of the outer peripheral surface of the sleeve 8 located outside the container 3 is attached to the drum-shaped photoreceptor 1 with an optimum interval for developing an electrostatic latent image formed on the outer peripheral surface of the drum-type photoreceptor 1 with a developer. is separated from the outer peripheral surface of the

The sleeve 8 extends longer than the magnet assembly 6 in the axial direction and has regions at both ends that do not face the magnet assembly 6. A blade 9 made of a non-magnetic material is attached to the lower part of the developing device. The leading edge of the blade 9 extends parallel to the axis of the sleeve 8 and is spaced apart from the outer peripheral surface of the sleeve 8 at a constant distance.

The blade 9 is movable up and down, and the amount of developer material 4 deposited on the sleeve 8 can be appropriately controlled by its movement.

The developer material scattering prevention member 10 constituted by a magnet prevents the developer material from being disposed on both ends of the sleeve 8 in the longitudinal direction and in close proximity along the outer peripheral surface of the sleeve 8 located inside the developer container 3. It is fixedly arranged in the container 3.

The optimum value for the distance between the member 10 and the sleeve 8 is determined by the particle size of the developer material 4 used, but good results can be obtained if the gap is larger than the particle size of the developer material. .

In the illustrated example, there is an axial spacing between the inner end of the member 10 and the end of the magnet assembly 6, but this spacing may be omitted and a portion of the member 10 may extend radially toward the magnet assembly 60. It can also be placed outward.

As shown in FIG. 1, the developer collecting member 11 is provided at the 100th order of the members with respect to the rotation direction B of the sleeve 80.

The collection member 11 is made of a non-magnetic material such as resin or special stainless steel, and is provided at the bottom of the container 3 and close to the sleeve 8 .

The retrieval member 11 has a first portion 11a that is close to the sleeve 8 and extends from the distal end of the sleeve 8 to at least a position below the end of the magnet assembly 6, and a second portion 11a that is inclined inwardly in the longitudinal direction of the sleeve 8. It consists of part 12.

Two annular rings 14 are respectively rotatably arranged on the fixed shaft 5 via bearings 15, and are fixed to the ends of the sleeve 8.

One of the annular rings 14 has a V-shaped groove 16 on its outer peripheral surface, and a belt 17 is stretched between the branch grooves 16 and a drive device (not shown), thereby causing the sleeve 8 to rotate in the direction of arrow B. do.

When the sleeve 8 is rotated in the direction of arrow B with the above-described configuration, the developer material 4 stored in the developer material container 3 is transferred to the sleeve 8 facing the circumferential portion of the magnet assembly 60 within the developer material container 3. It adheres to the outer peripheral surface of.

Excess developer material attached to the outer peripheral surface of the sleeve 8 is removed by the blade 9.
As the sleeve 80 rotates, an appropriate amount of the developing material scraped off by the developer material remaining on the outer peripheral surface of the sleeve 8 comes into contact with the surface of the photosensitive drum 1 and develops an electrostatic latent image.

When the sleeve 8 rotates, the developer material 4 tries to scatter out of the developing unit of the copying machine through both ends of the sleeve 8 in the longitudinal direction. The material is attracted onto the member 10 by the magnetic action of the member 10 .

As shown in FIG. 2, the developer adsorption member 10 is composed of a large number of semicircular magnets that are placed closely together so that adjacent portions are semicircular magnets of opposite polarity. Best results can be obtained when placed along the

Of course, it goes without saying that the developer adsorption member may be formed in other configurations, such as one semicircular magnet.

The developer material present on the areas at both ends of the sleeve 80 is
The developer material is either attracted to the developer attraction member 10 or separated from the sleeve 8 by the centrifugal force generated by the rotation of the sleeve 80 and blown out of the developing device 2 .

This blown developing material is removed from the portion 11 of the developing material collecting member 11.
This collected developer material collides with member 1 and is collected.
2 moves into the longitudinal direction of the sleeve 8, that is, within the range of the magnetic force of the magnet assembly 6, and is again attached to the sleeve 8 by the magnetic force of the magnet assembly 6.

FIG. 3 shows that in the apparatus shown in FIGS. 1 and 2,
FIG. 8 is a broken pressure surface view of a sleeve characterized by forming spiral grooves at both ends of the sleeve 80.

Reference numeral 18 indicates a sleeve 80 that does not face the magnet assembly 6
The branch grooves 18 are shown as spiral grooves cut into regions provided at both ends, and the branch grooves 18 are formed at an angle so as to have the function of moving the developing material inward in the longitudinal direction of the sleeve when the sleeve rotates.

The optimum value for the pitch of the grooves 18 varies depending on the particle size of the developer used, but good results can generally be obtained if the pitch is greater than or equal to the particle size of the developer.

When the above-mentioned groove is provided on the sleeve 8, the developer material on the groove itself is forced to move inside the sleeve 8 in the longitudinal direction while the sleeve 80 is rotating, that is, in a direction in which the developer material 4 does not scatter from the developing device to the outside. Therefore, when used together with the developer adsorption member 10, the ability to prevent developer scattering is further improved.

Furthermore, the use of branch grooves makes it possible to weaken the strength of the magnetic force of the developer material scattering prevention member 10, which has the advantage that the device itself can be manufactured at low cost.

Next, the present invention will be explained in detail.

In the apparatus shown in FIGS. 1 and 2, as the developing material adsorption member 10, a material in which ferrite particles are uniformly dispersed in rubber and magnetized as shown in FIG. A magnetic developer having a particle size of 16 μm was used, and the distance between the sleeve 8 and the developer adsorbing member 10 was set to 0.5 mm.

Furthermore, the photosensitive drum 10 peripheral speed was set to 125 mm/sec,
The outer diameter of the sleeve 8 is 32 mm, and the sleeve 8 is connected to a DC 1
It was rotated by a 00V, 5W electric motor, and the distance between the photosensitive drum 1 and the sleeve 80 was 1 mrn, and the distance between the sleeve 8 and the blade 90 was 0.4 mm.

When the sleeve 8 was rotated at 50 rpm under the above-mentioned conditions, the amount of scattering of the developer material was small enough to cause no practical problem.

Next, as shown in FIG. 3, the developing device was operated under the same conditions as described above, except that spiral grooves 18 with a pitch of 50 μm were formed on both ends of the sleeve 80, and the developer material was scattered. Good results were obtained with almost no visible signs.

In the above two embodiments, a one-component magnetic developer was used as the developer, but the apparatus of the present invention can also be applied to a two-component developer, such as a developer made of iron powder and carbon. It is.

As described above, the apparatus of the present invention is characterized in that developer material adsorption sound materials are provided close to both ends of the sleeve, thereby preventing the developer material from scattering.

In conventional sleeve-rotating magnetic roller developing devices, as mentioned above, an elastic body such as sponge or felt was brought into contact with the sleeve to prevent developer material from scattering. However, the apparatus of the present invention has the above-described structure to eliminate the above-mentioned disadvantages, and has the special effect of having a simple structure and excellent ability to prevent scattering of developer material. It is something that can be played.

Furthermore, in the present invention, the spiral groove 18 and the collection member 11
By providing this, the scattering of the developer material can be more completely prevented due to the synergistic effect with these members.

In particular, by configuring the collection member 11 as described above, the collected developer material is sucked into the sleeve 8 again and reused, so there is no wasteful consumption of the developer material, which is economical.
Furthermore, it has the advantage that there is no need to dispose of the collected developing material.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a rotating sleeve type magnetic roller developing device according to the present invention. FIG. 2 is a broken pressure surface view of the device shown in FIG. FIG. 3 is a broken pressure surface view of one embodiment of the sleeve used in the device of the present invention. Total...Developer material container, 4...Developer material, 6
... Magnet assembly, 8 ... Rotating sleeve, 10 ... Developer adsorption member, 11 ...
Developer collection member, 18...groove.

Claims (1)

[Claims] 1. A developer container for storing developer material; a cylindrical hollow sleeve made of a non-magnetic material that is rotatably attached to the container and has a part of its circumferential surface exposed from the container; A developing device for an electronic copying machine having a magnet disposed therein and a driving means for rotating the sleeve, comprising: a region formed at both longitudinal ends of the sleeve and not facing the magnet; and a region disposed close to the region. a magnetic attraction member that magnetically attracts the developer material on the region, a spiral groove formed in the region and that moves the developer material on the region into the inside of the sleeve in the longitudinal direction when the sleeve rotates; a developer collection member disposed next to the magnetic attraction member in terms of rotation method, the developer collection member extending close to the sleeve from an end of the sleeve to at least an end position of the magnet. a first portion that collects the developing material on the area that is not attracted by the magnetic attraction member; 1. A developing device for an electronic copying machine, characterized in that the developing device is comprised of a second portion that causes the transition to occur.